Unfair Hextech Re-rolls

I have been experiencing some very unfair re-rolls through the hextech crafting system. I had 4 4800 IP champions yet to be unlocked and 19 6300 IP champions. After rolling 12 times I no longer have any 4800 IP champions and still have 11 6300 champions. Now as far as I´m aware it was never reported that the odds were stacked against me so I didn´t think it was worth it to wait until I had manually unlocked all 4800 IP champions before re-rolling my champion shards.

I either want to confirm that this has just been extremely unlucky or if this is common, warn people who might also think that using the hextech system is a nice way of unlocking champions, it certainly hasn´t been for me.

• Oracle